I think ROTJ and TLJ already established her force-sensitivity pretty well without her spacewalk.

In ROTJ, Luke tells her of her power and she uses it a couple of times:
“Somehow, I’ve always known…”
“He wasn’t. I can feel it…”

In TLJ, she has a mother-son force interaction with Kylo-Ren just before the bridge explosion, and she connects with Luke from her hospital bed.

I also just want to clarify that I don’t dislike the spacewalk because of how powerful/not powerful Leia is supposed to be. My brain just could never muster enough suspension of disbelief to accept that anyone blown into outer space can survive. I know there are studies suggesting it could be possible to survive for a minute or two, but in my mind, basic logic and storytelling dictates that she should have died. I would feel exactly the same if it were Luke.

I don’t like the head fake of making us think she’s dead and then using the force as a deus ex machina to get her out of the situation. It cheapens the stakes for me. I’m okay with it in Guardians of the Galaxy, because that plays a lot more fast and loose with the rules and is just plain fun (it’s also actually set up better than what happens in TLJ). But in Star Wars, that’s a basic rule of logic that I think should stick.